Conventionally, in optical communications using an optical transmission member such as an optical fiber and an optical waveguide, an optical module including a light emitting element such as a surface-emitting laser (for example, a vertical cavity surface emitting laser (VCSEL)) has been used. The optical module includes one or more photoelectric conversion elements (light emitting elements and light receiving elements), and a light coupling element for transmission or reception (hereinafter referred to also as “optical receptacle”) (see, for example, PTL 1).
FIG. 1 illustrates a configuration of optical module 10 disclosed in PTL 1. FIGS. 2A to 2D illustrate a configuration of light coupling element 40 disclosed in PTL 1. FIG. 2A is a plan view of light coupling element 40, FIG. 2B is a bottom view of light coupling element 40, FIG. 2C is a front view of light coupling element 40, and FIG. 2D is a right side view of light coupling element 40.
As illustrated in FIG. 1, optical module 10 disclosed in PTL 1 includes substrate 20, photoelectric conversion element 30 disposed on substrate 20, and light coupling element 40 disposed on substrate 20. Substrate 20 includes substrate main body 21, and first positioning protrusion 22 disposed on substrate main body 21. As illustrated in FIGS. 2A to 2D, light coupling element 40 includes recess 41 disposed on the surface facing substrate 20, first lens surface 42 (incidence surface) on which light from photoelectric conversion element 30 is incident, total reflection surface 43 (reflection surface) configured to reflect light incident on first lens surface 42, second lens surface 44 (emission surface) configured to emit light reflected by total reflection surface 43 toward an end surface of optical fiber 50, second positioning protrusion 45 configured to set the position of optical fiber 50 with respect to light coupling element 40, and second positioning recess 46 configured to set the position of photoelectric conversion element 30 with respect to light coupling element 40 at substrate 20.
As illustrated in FIG. 1, at the time of assembling optical module 10 disclosed in PTL 1, first, second positioning recess 46 of light coupling element 40 is fit to first positioning protrusion 22 of substrate 20 on which photoelectric conversion element 30 is disposed. Next, first positioning recess 52 of ferrule 51 supporting optical fiber 50 is fit to second positioning protrusion 45 of light coupling element 40. In this manner, in optical module 10 disclosed in PTL 1, photoelectric conversion element 30 and optical fiber 50 are optically connected with each other.